This particular part used to work, but has not worked in recent months (may or may not have been caused by upgrade to 5.1. Upgrading to 5.3 did not effect a change on this behavior).

I am able to access Inventory > People, which displays the various groups as populated by Active Directory.

When I click on a group, the information for the first user in that group shows up correctly. Clicking another person causes the loading wheel to spin, and it will spin indefinitely. Attempting to pull up the first person's information by clicking on them causes the loading wheel to spin. Going back to Inventory > People, and clicking on the group pulls up the information for the first person correctly.